Psychology
The Sunk Cost Fallacy and Irrational Escalation in Business Decisions
Quick fact
In a classic experiment, people were more likely to continue a failing project when they had made a prior investment, even when new information showed the project was doomed. This bias can lead companies to pour billions into projects that should have been abandoned long ago.
Why this is interesting
Have you ever sat through a terrible movie just because you paid for the ticket? That’s the sunk cost fallacy—and it happens in business all the time, but with millions of dollars at stake.
Read the full explanation
Understanding The Sunk Cost Fallacy and Irrational Escalation in Business Decisions
Imagine you’re at a buffet and you’ve already eaten a lot. You’re full, but you feel you must eat more because you paid for the meal. That extra food doesn’t give you any benefit—it actually makes you uncomfortable. The money is already spent; it cannot be recovered. In business, the CEO of a failing product sees the millions already spent on development and thinks, "We can’t stop now—we’ve invested too much." But the past investment is gone. The only thing that matters for the future decision is whether continuing will bring more benefits than costs. The sunk cost fallacy is the irrational tendency to let those past costs influence the decision, even though they are irrelevant. This often leads to what psychologists call "escalation of commitment": people keep investing more resources in a losing course of action to justify the original investment.
A deeper explanation
The sunk cost fallacy arises from several psychological mechanisms. First, loss aversion: we feel losses more intensely than equivalent gains. Stopping a project feels like a loss of everything invested, while continuing offers hope of eventual success. Second, cognitive dissonance: we want to believe our past decisions were correct, so we rationalize continuing rather than admitting a mistake. Third, self-justification: abandoning a project means admitting failure, which threatens self-image and external reputation. In business, these psychological forces are amplified by social pressures—managers may fear being seen as wasteful, or they may have personal stakes in a project’s success. Over time, this leads to escalating commitment, where each incremental investment seems justifiable because it builds on the previous ones, even when the project is clearly doomed. The rational approach is to base decisions solely on future costs and benefits—what economists call the "marginal analysis." By recognizing sunk costs as irrelevant, decision-makers can cut losses early and redirect resources to more promising opportunities. This is why many companies use pre-set decision criteria and post-mortem reviews to prevent emotional attachment from distorting strategic choices.